In this study, we describe how to obtain high-quality Al₂O₃ dielectric thin films and their implementation in In₂O₃ thin film transistors by combining plasma treatment and combustion process at low temperatures (250 °C). The single layer Al₂O₃ dielectric formed by this technique exhibited a higher areal capacitance and a lower leakage level compared with those of conventional solution-processed Al₂O₃. The resulting TFTs presented a superior electrical performance at a low operating voltage of 2 V, with a positive threshold voltage of 0.39 V, a subthreshold swing of 0.V/decade, an On/Off ratio of 1.8×10⁴, and a superior mobility of 136 cm² V^-1 s^-1.